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Patenta& Sept. 19,' 1922..

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/A/ l/flvfl? A. COTTON. SUPERHEATER BOILER. APPLICATION FILED APR. 12, !920.

A. COTTON. SUPERHEATER BOILER. APPLc ToN FILED APR. 12. 1920.

Patentesep 3 SHEETS-SHEET 2.

A. COTTON. SUPERHE ATER B0lLER. APPLICATION HLED AFR. 12, 1920.

Patenteasept. 19 1922.

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//v VIA/7077 AZ: 77727) Cfj M Patented Sept. 19, 1922..

UNITEDSTATES -PATENT OFFICE.

ALFRED COTTON, OF ST. LOUIS, MISSOUEI, ASSIGNOR TO HEINE BOILER COMPANY, OF

' ST. LOUIS, MISSOUR, .A COR PORATION OF MISSOURI.

SUPERHEATEE BQILER. i

To all 'w ?tom it may concern:

'Be it known that I, ALFRED COTTON, a cti-- zen of the' United States, residing at St. Lous, Mssour, have nvented a certan new and useful Improvement in Superheater 'Boilers, of which the following is a full,

clear, and exact description, suchas will en"- able others skilled in the art to which it appertains to'make and use the same.

This inventon relates to Watertube boilers of the Stirlingtype. e

The main object of the invention isto provide a superheater'boiler that is'superi'or to the usual Stirling boiler, in' that it pro duces drcr stcam; it insures more complete combustion of 'the fuel {and elminates smoke; it has a greater steaming Capacity and t s less expensive to manufacture than many kinds cf Stirling boilers now in use.`

Another object is toprovide a superheater boler of the Stirlingtype which' is so designed that greater latitude is allowed in the arrangement of the superheater. a

Briefly described my present invention consists 'a water tube boiler comprising four banks' of water `tubes and drums arranged so 'that the water will circulate up wardly from the mud drum or feed water chamber through' the first and second banks of i tubes *and return to the mud l drum' through the third bank of tubes or mainly through the third bank and partly through the fourth bank of tubes through which the feed water is supplied to 'the mud drum and a superheater arranged in such a manner that it will be heated by the gases traveling through the boiler. lt embodies all of the good features and characteristics of the four bank boiler described in my ending application' for patent SerialNo. 366,286,'filed March `16, 1920, with the addedadvantage of a I eliminate the possibility of water becom ing. entrainedwith the steam and carried into the space from which the supply of steam Application filed Aprl 12, 1920. Serial No. 373348.

is taken, T eliminate the possibility of the water'level in the rear elevated drum drop png sufliciently to expose the upper ends of the feed water tubes and cause them to become dry and overheated to'such a degree that their expanded joints leak, and I eliminate the possibility of the furnace gases becoming chilled below their ignition point ber fore combustion is completed, thus resulting in loss of ethciency', and the production of heavy smoke', all as explained clearly in my pending application for patent previously referred to.

Figure l of the drawngs is a vertical sectonal View of a s uperheater boiler constructed in accordance with my invention.

Figure Q'is" a similar View showing the superheater arranged in a slightly different manner; and

Figure 3 is a 'vertical sectional view of a superheater boiler embodying my invention and provided with a submerged drum that communicates with the upper ends of the tubes of the radiant heat bank.

Referring to Figure l of the drawings, which illustrates one form of my invention, A designates a set of water tubes which may be called the radiant heat bank of the boler, B designates another set of water tubes which may be called the convected heat bank, C designates -another set of Water tubes which may be called the downcomer bank and D designates another set of water tubes which may be' called the economizer bank. The radiaut heat bank A and the convected heat bank B lead upwardly from the mud drum or feed water chamber l to a front steam-and-water drum 2 and to a middle steam-and-water drum 3, respectively. The downcomer bank C leads downwardly from the middle drum 3 to the mud drum 1 and the economizer bank D through which the feed water is supplied to the mud drum leads downwardly to the mud drum from the rear steam-and-water drum 4-.

The front bank or radiant heat bank A consists of only a few rows of tubes that are exposed to the radiant' heat of the fire and of the combustion chamber m. Preferably this radiant heat bank is composed of two rows of tubes which are the only tubes discharging into the front steam-and-water drum 2, but if clesired, the radiant heat bank A may consist of three rows of tubes. In

all cases, however, the cross-sectional area of the tubes of the radiant heat bank will be less than the cross-sectional area of the tubes of the convected heat bank B. The front drum 2 is connected to the middle drum 3 by means of water circulators 75 and steam circulators 6 and said middle drum is connected with the rear drum a preferably by means of water circulators 7 and steam circulators 8, the outlet 9 for the steam produced in the boiler preferably leading rrom the upper side of the rear drum 4.

The baflies of the boiler can be arranged in various ways without departing from the spirit of my invention, so long as the boile' is cquipped with tour banks of tubes combined with a mud drum or feed water chamber and elevated drums or chambers in such a manner that the water that circulates upwardly from the mud drum will enter separate and distinct drums or chambers that communicate with the first and second tube banks of the boiler, and a superheater arranged in such a manner that it will be heated by some of the gases fiowing through the boiler. In the form of my invention illustrated in Figure 1 a trent bafile 10 ex tends upwardly from the mud drum l at the rear side of the radiant heat bank A to a point in proximity to the front steam-andater drum 2, a second batlie 11 is arranged at the :front side ot the down-comer bank C and extends downwardly from the middle steam-and-water drum 3 to a point in proximity to the mud drum i and a third bafiie 12 is arranged between the down-comer bank C and the economizer bank D, so as to cause the gases to flow upwardly between the tubes of the down-comer bank C, then downwardly between the tubes of the economizer bank to an outlet 13.

Since the flow of steam and water into the front steam-and-water drum 2 is very much less in my boiler than in the usual Stirling boiler, the water in the front drum of the boiler is much calmer and a much better separation of the steam and water is obtained. Furthermore, there is little liability of the water level in the front drum 2 rising abnormally or the water becoming entrained with the steam and carried over with the steam into the steam space of the middle drum 3, thus insuring the production of drier steam, even when the boiler is driven at rates much higher than is considered reasonable practice with the nsual Stirling boiler.

Since the water fiowing up the convected heat bank B flows directly across the middle steam-and-water drum 3, without having to encounter the resistance to flow of any water circulators, as in the regular Stirling boiler, the flow to the down-comer bank C is tree. The water circulators 7 leading from the middle drum 3 to the rear drum 4 raise the temperature of the feed water sufiiciently to prevent corrosion on the tubes of the economizer bank caused by condensation ot wated vapor in the gases fiowing through the last pass of the boiler. The flow of the water through the circulators 7 also tends to prevent the level of the water in the rear drum 4 from dropping abnormally, but in view of the fact that my boiler is so constructed that there is practically no restriction to the circulation of the water upwardly from the mud drum the lowering ,of the water level in the rear drum t is unobj ectionable, even at high driving rates.

In a boiler of the Construction above de scribed three spaces are available for a superheater, and the choice .of position is dictated by the amount of superheat desired, namely, the temperature of the superheated steam. The gases fiowing in 'the space between the first and second banks are too hot for the amount of superheat generally required. may be regulated by controlling the amountof gases flowing over the superheater, as in the form of my invention illustrated in Figure 2 and hereinatter described, it is inadvisable to use gases hotter than necessary, as this causes the superheater elements to deteriorate rapidly. The temperature of the gases flowing in the space between the thrd and fourth banks of tubes is so much reduced that only a small degree of superheat would result, unless an impractically large superheater were used. In general practice I pretor to arrange a superheater E between the second and third banks B and C, on account of the fact that the gases flowing through this space are of such a temperature that the amount of superheat required in usual practice is easily attained with a compact superheater that can be used tor a long period without the elements of same deteriorating. In Figure 1 of the drawings I have shown my improved boiler equipped with a superheater E arranged so that the gases Will flow downwardly over same and over the tubes of the second bank in one common pass. The amount of gases fiowing over each course can be accurately con-- trolled, but I prefer to arrange one or more horiZontally-disposed battle shelves lO on the rear side of the front battle 10 and a horizontally-disposed baflie shelf 11 at a, point between the superheater E and the convected heat bank B, so as to cause the gases that flow over the upper edge of the 'front battle 10 to flow downwardly over the convected heat bank B and also over the superheater E and then flow upwardly among the tubes of the down-comer bank C, as indicated by arrows in Figure 1, said gases escaping downwardly through the last pass to the outlet 13. It is not essential, however, that the superheater and the baf- Although the superheat fles be arranged in the manner shown in Figure l, tor if desired, the boiler can be so constructed *that the' gases fiowing over the superheater will be in common with the gases flowing along the third bank.

In Figure 2 of the drawings T have shown the" superheater E arranged between a battle ll located in the 'front portion 'of the down-comer bank C', and a battle 14 ar-- ranged at the rear side of the connected heat bank B, the upper end of said bar'lle lt being spaced away from themiddle drum', and e the lower end of said battle being spaced away from the'mud drum l, so as to cause part or" the gases to flow downwardly` over the convected heat bank E and 'the re-` mander of the gases to enter the upper end of the superheater chamber and flow downwardly through same, as indicated by the arrows in Figure 2. A damper 15 is preterably provided so as to enablethe amount of superheat to be accurately controlled. The fact that the draft pressure at the outlet or lower end of the superheater chamber is less than the draft pressure at the inlet to said chamber insures an ample flow of hot gases through the superheater chamber when the damper 15 is open. The gases which have passed over the superheater E are still at a sufiicientl hi 'h tem aerature" to give up a considerable quantity of heat to the cooler heating surface of the boiler, and consequently, the gases which escape from the superheater chamber can be returned to the main body of gases early enough to transmit heat to the third and fourth tube banks of the boiler.

The spaces between the various banks of tubes of my 'improved boiler are just as accessible as in the usual Stirling boiler, and.

as there is one additional space, greater latitude is allowed in the arrangement of the superheater. The space ot the boiler in which it is desired to locate the superheatcr can be increased sufciently to accommodate the superheater and to provide sufiicient room tor 'access to the superheater, as well as to the boiler tubes,` by slightly reducing the size of the other two spaces between the banks of tubes.

In Figura 3 of the drawings l have illustrated still another form of my invention, wherein the radiant heat banka-*L leads upwardly from the mud drum l to a submerged water drum F. In all other respects the boiler shown in Figure 3 is substantially the same as the boiler shown in Figure l, except that steam circulators are not arranged between the submerged water drum and the steam-and-water drum 3.

Having thus described my invention,

what I claim as new and desire to secure by 4 one Ol .said elevated drums and constituting the sole source of water suppl to said elevated drum, separate and distinct convected l t` bank of upfiow tuhes spaced away 'from said radiant heat bank and con-- nected to the other elevated drum for causin the remainder of the water rising from mud drum to circulate upwardly to said other elevated druni, a baffie arranged between said radiant heat bank and said ronvected heat bank, a co-operating bathe tor causing the lire gases flow downwardly among the tubes of the convected heat bank, downcomer tubes leading from one of said elevated drums direct-ly to said mud drum, and a superheater arranged so that' it will be heated by gasee fiowing through the boiler.

2. A water tube boiler, comprising three elevated 'transverse steam-and-water drums, water circulators connecting the front drum withthe middle drum, a transverse mud drum, a radiant heat bank of upfiow tubes leading upwardly from the mud drum to the front steam-and-water drum and con stituting the sole source ot water supply to said 'front drum, a separate and distinct convectedheat bank of upflow tubes leading upwardly from the mud drum to the middle drum for causing the remainder of the water supplied to said mud drum to cir- `culate upwardly to said middle drum, a`

bafiie arranged between the radant heat bank` and the convected heat bank, downcomer tubes leading from the middle drum 'to the mud drum, an economizer bank of tubes leading froni the rear steam-and water drum to the mud drum, and a superheater arranged in a space between two adjacent tube banks or" the boiler.

3. A water tube boiler, comprising three elevated transverse steam-and-water drums, steam-and-water circulators connect-ing the front drum with the middle drum and the middle drum with the rear drum, a trans- Verse mud drum, a radiant heat bank of upflow tubes leading upwardly from the mud drum to the front steam-and-water drum and constituting the sole source of water supply to said front drum, a separate and distinct convected heat bank of upfiow tubes spaced away from the radiant heat bank for conducting the remainder of the water supplied to the mud drum upwardly to the middle steam-and-water drum, a baile arranged between the radiant heat bank and the convected heat bank and a co-operating battle for causing the fire gases to flow downwardly among the tubes of the con- Vected heat bank, downcomer tubes leading from the middle steam-and-water drum to the mud drum, an econonzer bank of tubes Ieading from the rear stean-xndwater drum to the mud drum, and a superheater arranged in the space between the cou- Vected heart bank and the downcomer tubes.

t. A Water tube botcr, conprsng at least two elevated transverse stea'n-and- Water drums, a trunsverse mud drum a redan; heat first bank ot" upow tubes leading; fron the mud drum to the front steamend-Water drum and arranged at the reur of the conbuston j-hamber outside of the mein path ot' flow of the geses, Water circulators connectng said eevated steam-and- Water drums together, a convected heat second bank of upfiow tubes leading from the nud drum to the second steam-and-Water drum tor causing the renander of the Water rsng from the mud drum to pass directly 'into said second stean-and-water drum, a baffie between the first and second banks, downconer tubes leading from the Second steam-and-Water drum directly into said mud drum, and a superheater arranged in the space between the convected hest bank and the downcouer tubes.

ALFRED COTTON. 

